The present invention relates to a lens barrel holding a lens or a lens group, and a photographing apparatus provided with the lens barrel.
In a camera which is provided with the lens barrel and used for photographing, (hereinafter, described as a photographing apparatus), there is a camera of a type in which the lens barrel holding the lens or lens group is structured so that it can conduct the telescopic motion in the optical axis direction by a plurality of barrel bodies, and the lens held inside the lens barrel is moved and the focusing (hereinafter, described as focusing) or the magnification change is conducted, or after it is used, the lens barrel is retracted and stored in the main body of the photographing apparatus. Such a lens barrel is structured in such a manner that, in an inner periphery or outer periphery of a plurality of barrel bodies constituting the lens barrel, for example, such as the lens barrel holding the lens group, a helicoid mechanism or cam mechanism is provided, and when at least one hand of those barrel bodies is rotated, the barrel bodies are moved each other in the optical axis direction.
Further, in such a lens barrel, there is used the cam or helicoid mechanism to conduct the focusing and magnification change, and the cam and helicoid mechanism to protrude and retract the lens barrel from the stored position (collapsing position) to the operating position, are continuously formed, and the lens barrel structured so that the protruding and retracting operation and the focusing and magnification change operation of the lens barrel can be smoothly conducted by the same drive mechanism.
Then, in such a helicoid or dam, it is conducted that, when a lead angle of a portion at which the protruding and retracting operation is conducted, that is, when a guide angle in the optical direction to the peripheral direction of the lens barrel is largely set, the movement distance to the rotation of the barrel body is made large, and the lens barrel is effectively retracted.
Further, in the photographing apparatus, there is an apparatus provided with an automatic opening and closing type barrier in the forefront portion of the lens barrel, and at the operation time, the barrier is opened and the lens is exposed, and at the time of storing, the barrier is closed and the lens is protected. In this barrier opening and closing mechanism, there is a mechanism structured so that it is operated by being interlocked with the protruding and retracting operation of the lens barrel, and so that, when the retraction of the lens barrel to the storing position is completed, the drive mechanism of the lens barrier is operated, and the barrier is closed.
However, in the photographing apparatus provided with such a lens barrel, in the case where the lens is retracted, when the drive mechanism of the lens barrel is stopped, there is a problem that, by an error of the rotation stop position of the barrel body, the position in the optical axis direction is dislocated, when the retraction of the lens barrel is completed. When there is a dislocation of the position when the lens barrel is retracted, the appearance of the photographing apparatus is injured.
Further, when the barrier operated being interlocked with the protruding and retracting operation of the lens barrel is provided, by the dislocation of the position of the lens barrel when the retraction of the lens barrel is completed, there is also a possibility that the operation error is generated, like that the closing of the barrier becomes imperfect.
The object of the present invention is to provide a lens barrel and a photographing apparatus equipped therewith by which the dislocation of the stop position when the retraction of the lens barrel is completed, can be reduced.
The above-described object can be attained by any one of Structures (1) to (3).
(1) In the lens barrel, it has the following structure: an outer barrel on an inner peripheral surface of which, a guide section is formed; and an inner barrel which holds a lens and on an outer peripheral surface of which, a guided section engaged with the guide section is formed, and which is moved in the optical axis direction by the rotation of the outer barrel, wherein the guide section has a guiding portion for introducing the inner barrel into a plurality of positions including the operating position and the storing position; and the guiding portion has the first guiding part, and the second guiding part formed so that it is continued to the first guiding part, and has the different lead angle from the first guiding part, and the third guiding part which is continued to the second guiding part and is formed so that it has a lead angle which is smaller than the second guiding part, and has almost the same lead angle as the first guiding part; and at the storing position, the inner barrel is positioned within the area in which the guided section can be engaged with the third guiding part.
(2) In the lens barrel, it has the following structure: an outer barrel on an inner peripheral surface of which, a guide section is formed; and an inner barrel which holds a lens and on an outer peripheral surface of which, a guided section engaged with the guide section is formed, and which is moved in the optical axis direction by the rotation of the outer barrel, wherein the inner barrel can move from the storing position to the operating position; and the guide section has a guiding portion to introduce the inner barrel from the operating position into the storing position; the guiding portion is structured including the first guiding part positioned on the operating position side and the second guiding part formed continuously to the first guiding part; the lead angle of the second guiding part is formed to be larger than 0xc2x0, and smaller than the lead angle of the first guiding part; and in the storing position, the inner barrel is positioned within an area in which the guided section can be engaged with the second guiding part.
(3) In the photographing apparatus, it has a lens barrel including the following structure: an outer barrel on an inner peripheral surface of which, a guide section is formed; and an inner barrel which holds a lens and on an outer peripheral surface of which, a guided section engaged with the guide section is formed, and which is moved in the optical axis direction by the rotation of the outer barrel; the guide section has a guiding portion for introducing the inner barrel into a plurality of positions including the operating position and the storing position; and the guiding portion has the first guiding part, and the second guiding part formed so that it is continued to the first guiding part, and has the different lead angle from the first guiding part, and the third guiding part which is continued to the second guiding part and is formed so that it has a lead angle which is smaller than the second guiding part, and has almost the same lead angle as the first guiding part, wherein at the storing position, the inner barrel is positioned within the area in which the guided section can be engaged with the third guiding part; it has a drive means for driving the female helicoid cylinder, and a control means for controlling the drive means; and the control means controls the drive means to move male helicoid cylinder from the storing position to the operating position.
Furthermore, the more preferable Structures (4) to (11) are as follows.
(4) A lens barrel which has: an outer barrel on an inner peripheral surface of which, a guide section is formed; and an inner barrel which holds a lens and on an outer peripheral surface of which, a guided section engaged with the guide section is formed, and which is moved in the optical axis direction by the rotation of the outer barrel; and the lens barrel in which the inner barrel is moved from the storing position to the operating position, the lens barrel is characterized in that: the guide section has a guiding portion for introducing the inner barrel from the operating position into the storing position direction; and the guiding portion is structured including the first guiding part positioned on the operating position side, and the second guiding part formed so that it is continued to the first guiding part; and the lead angle of the second guiding part is formed to be smaller than the lead angle of the first guiding part; and at the storing position, the inner barrel is positioned within the area in which the guided section can be engaged with the second guiding part.
Herein, the guide section and the guided section implies a cam structure by the cam and the protrusion such as a cam pin, or a helicoid structure. Further, the lead angle implies an angle formed in the optical axis direction, to the peripheral direction almost perpendicular to the optical axis direction of the lens barrel. Further, the xe2x80x9coperating positionxe2x80x9d is a position of the inner barrel to the outer barrel in the lens barrel which is in the state that the photographing can be conducted. In this operating position, the inner barrel is further moved to the outer barrel, and the focusing or the magnification change may also be conducted, and an area at which the inner barrel can be positioned in the state that the photographing can be conducted is included in the operating position.
Further, the xe2x80x9cstoring positionxe2x80x9d is a position of the inner barrel to the outer barrel when the retraction of the inner barrel is completed at a time when the inner barrel is retracted into the outer barrel and is made compact at the no-use time of the lens barrel. Hereupon, a predetermined position of the inner barrel to the outer barrel which is previously set as the optimum position at which the inner barrel is stopped at the time of the retraction is defined as a xe2x80x9cpredetermined optimum storing positionxe2x80x9d. That is, the xe2x80x9cactual storing positionxe2x80x9d is a position at which actually the inner barrel stops, to the xe2x80x9cpredetermined optimum storing positionxe2x80x9d. In addition, the lens barrel when the inner barrel is at the operating position is defined as a xe2x80x9cusing statexe2x80x9d and the lens barrel when the inner barrel is retracted into the storing position is defined as a xe2x80x9cstoring statexe2x80x9d.
According to Structure (4), in the outer barrel and inner barrel constituting the lens barrel, the guide section of the outer barrel has the first and second guiding parts, and the lead angle of the second guiding part is formed to be not larger than the lead angle of the first guiding part. Further, in the storing position, the inner barrel is positioned within an area in which the guided section is engaged with the second guiding part. That is, when the inner barrel is moved from the operating position to the storing position to the outer barrel, the guided section is introduced according to the guide section of the outer barrel, and the inner barrel moves a necessary distance along the first guiding part quickly, and in near the storing position, is engaged with the second guiding part, and gradually moved and arrived at the storing position. Accordingly, at the time when the retraction is completed, because the dislocation between the predetermined optimum storing position and the actual storing position of the inner barrel is reduced, the appearance of the lens when the retraction of the inner barrel is completed, becomes good. Further, for example, when the barrier which is moved being interlocked with the protruding and retracting operation of the inner barrel is provided in the lens barrel, because it can be prevented that the operation error is generated, like as that the storing position of the inner barrel is dislocated from the predetermined optimum storing position and the closing of the barrier is imperfect, it is preferable.
(5) A lens barrel which has: a female helicoid cylinder on whose inner peripheral surface, the female helicoid is formed; and a male helicoid cylinder which holds the lens, and on whose outer peripheral surface, the male helicoid which is engaged with the female helicoid is formed, and which moves in the optical axis direction by the rotation of the female helicoid cylinder, the lens barrel is characterized in that: the female helicoid is made as a compound female helicoid structured by the first female helicoid portion, and the second female helicoid portion which is formed so that it is continued to the first female helicoid portion and which has the lead angle different from the first female helicoid portion, and the third female helicoid portion which is formed so that it is continued to the second female helicoid portion and which has the lead angle not larger than the second female helicoid portion; and the male helicoid in the male helicoid cylinder is made as a compound male helicoid provided with: the first male helicoid portion engaged with the first female helicoid portion; the second male helicoid portion engaged with the second female helicoid portion; and the third male helicoid portion engaged with the third female helicoid portion; and the third female helicoid portion moves the male helicoid cylinder in the optical axis direction for the protruding or retracting operation.
According to Structure (5), when the third female helicoid portion whose lead angle is smaller than the second female helicoid portion is formed, at the time of protruding and retracting operation, the male helicoid cylinder is gradually moved to the female helicoid cylinder and arrives at the storing position. Accordingly, because the dislocation between the actual storing position and the storing target position of the male helicoid cylinder to the female helicoid cylinder is reduced, the appearance at the storing time of the lens barrel becomes good. Further, for example, when the barrier which is moved being interlocked with the protruding and retracting operation of the male helicoid cylinder is provided, because it can also be prevented that the operation error of the barrier is generated by the dislocation between the actual storing position and storing target position, it is preferable.
(6) A lens barrel described in Structure (5) is characterized in that: the first female helicoid portion moves the male helicoid cylinder in the optical axis direction for the focusing operation.
According to Structure (6), it is of course that the effect of the invention described in Structure (2) is attained, and the first female helicoid portion is set to an adequate lead angle for the focusing, and the second and third female helicoid portions are adequately set to an adequate lead angle for the operation except for the focusing, that is, for the protruding and retracting operation, and can be used. Accordingly, the focusing operation, and the protruding and retracting operation can be respectively preferably conducted.
(7) A lens barrel described in Structure (5) or (6), which is characterized in that: the second female helicoid portion moves the male helicoid cylinder in the optical axis direction for the protruding and retracting operation which is faster than the third female helicoid portion.
According to Structure (7), because the lead angle of the second helicoid portion is set large, the movement distance of the male helicoid cylinder at the time of the protruding and retracting operation can be made large. Accordingly, the reduction of the thickness of the apparatus provide with the lens barrel, for example, the reduction of the thickness of the apparatus such as the photographing apparatus can be intended. Further, at the time of the protruding and retracting operation, because the male helicoid cylinder can be moved faster than the third female helicoid portion, and the switching between the storing state and the using state of the lens barrel can be conducted quickly, it is preferable.
(8) A lens barrel described in any one of Structures (5) to (7), which is characterized in that: the first female helicoid portion and the third female helicoid portion are formed into the almost same lead angle.
According to Structure (8), when the first female helicoid portion and the third female helicoid portion are formed into the almost same lead angle, in the male helicoid, the first male helicoid portion and the second male helicoid portion are formed, and in the first male helicoid portion, they can be made to engage with both of the first and the third female helicoid portions. Accordingly, because the shape of the male helicoid can be made simple, and the contact surface when it is engaged with the female helicoid can be made large, the male helicoid cylinder and the female helicoid cylinder can be preferably engaged without play. Further, when the contact surface of the male helicoid with the female helicoid is increased, because it can be prevented that the external light leaks into the lens barrel from between the male helicoid cylinder and the female helicoid cylinder, it is preferable.
(9) A lens barrel described in any one of Structures (5) to (8), which is characterized in that: the engagement length in the peripheral direction of the first male helicoid portion with the first female helicoid portion is longer than the engagement length in the peripheral direction of the second male helicoid portion with the second female helicoid portion.
According to Structure (9), when the engagement length of the peripheral direction of the first male helicoid portion with the first female helicoid portion is made long, the contact area of the male helicoid cylinder with the female helicoid cylinder can be large, and they can be preferably engaged without play. Accordingly, when the first male helicoid portion is used for the focusing operation, the focusing operation can be more precisely conducted. Further, when the first and third helicoids are formed into the same lead angle, because the strength of the engagement of the male helicoid cylinder with the female helicoid cylinder in the storing state, is increased, and at the time of the storing, the male helicoid cylinder can be more accurately retracted to the storing target position, it is preferable.
(10) A lens barrel described in any one of Structures (5) to (9), which is characterized in that: the adjoining compound male helicoids of at least one portion of the compound male helicoid provided on the outer periphery of the male helicoid cylinder are provided such that at least one portion viewed from the optical axis direction is mutually overlapped.
According to Structure (10), in the engagement of the female helicoid with the male helicoid, because, in an at least one portion of the peripheral direction, the female helicoid is nipped by two adjoining compound male helicoids, the male helicoid cylinder can be preferably assembled with the female helicoid cylinder without play. Further, when a portion of the adjoining compound male helicoids is overlapped with each other when viewed from the optical axis direction, because it can be prevented that the external light leaks into the lens barrel from between the male helicoid cylinder and female helicoid cylinder, it is preferable.
(11) A photographing apparatus which is provided with: a lens barrel which has a female helicoid cylinder on whose inner peripheral surface the female helicoid and the cam are formed; and a male helicoid cylinder which holds the lens and on whose outer peripheral surface the male helicoid which is engaged with the female helicoid is formed, and which is moved by the rotation of the female helicoid cylinder in the optical axis direction; a drive means for driving the female helicoid cylinder; and a control means for controlling the drive means, the photographic apparatus is characterized in that: the drive means is controlled by the control means, and the male helicoid cylinder is moved from the storing position to the operating position, and as the lens barrel, the female helicoid is made a compound female helicoid formed of the first female helicoid portion, and the second female helicoid portion formed so that it is continued to the first female helicoid portion and it has the different lead angle from the first female helicoid portion, and the third female helicoid portion formed so that it is continued to the second female helicoid portion and it has the smaller lead angle than the second female helicoid portion; and the male helicoid in the male helicoid cylinder is made a compound male helicoid provided with the first male helicoid portion which is engaged with the first female helicoid portion and the third female helicoid portion, and the second male helicoid portion which is engaged with the second female helicoid portion, and at the storing position, the first male helicoid portion is positioned at an area which is engaged with the third female helicoid portion.
According to Structure (11), the male helicoid cylinder is structured in such a manner that, at the storing position, the first male helicoid portion is positioned at an area which is engaged with the third female helicoid portion formed into the smaller lead angle than the lead angle of the second female helicoid portion. Accordingly, also in the photographing apparatus which has the drive means and the control means, and automatically moves the male helicoid cylinder from the operating position to the storing position, the dislocation between the actual storing position and the predetermined optimum storing position of the male helicoid cylinder to the female helicoid cylinder is reduced. As the result, the appearance of the lens barrel in the storing state becomes good. Further, for example, even when a barrier which is operated being interlocked with the protruding and retracting operation of the lens barrel is provided, because the generation of the operation error of the barrier can be prevented, it is preferable.